Joseph cavallt



UNITED STATES PATENT OFFIcE.

JOSEPH OAVALLI, OF LONDON, ENGLAND.

METHOD OF O'RNAMENTING IRON TABLETS.

SPECIFICATION forming part of Letters Patent No. 465,833, dated December29, 1891.

Application filed April 17, 1891. Serial No. 389,347. (No specimens.)Patented in England June 4, 1890, lilo. 6,787.

To etZZ whmn it they concern:

Be it known that I, JOSEPH OAVALLI, lithographer, a subject of HerMajesty the Queen of Great Britain, residing at 192 Kennington ParkRoad, London, in the county of Surrey, England, have invented certainnew and useful Improvements in Treating Iron Tablets for Ornamental andAdvertising Purposes, (for which I have obtained a patent in GreatBritain, No. 6,787, bearing date June 4,1890,) of which the following isa specification.

My invention relates to an improved method of treating iron tablets forornamental and advertising purposes generally, and is term ed by melitho-smalto iron, and by the means hereinafter explained I am enabledto permanently fix upon said tablets any subject that can be producedupon or by a lithographic stone, such as maps, plans, sketches, ordrawin gs, in any color or colors.

In carrying my invention into effect, I draw or sketch upon alithographic stone, or use a lithographic stone upon which is alreadydrawn or sketched the subject desired to be reproduced upon the irontablet. I then procure two pieces of cardboard, preferably of the samesize as the iron tablet. Each of said cards I coat upon one side with asolution of gum-arabic, or any other suitable gum of a like nature, andplace them aside to dry. The iron tablet intended to receive the designpreviously drawn upon the stone I coat upon'one side with a suitableenamel, which may be of any of the best kinds in general use for thatpurpose. \Vhen said enamel is set and hard and the gum upon the cards isdry, I pass the latter between press-rolls so as to insure a perfectlytrue and even surface upon the gummed or glazed side thereof. Upon oneof said cards I take an impression of the subject drawn upon the stonepreviously mentioned, but in substitution of the usual ink I use apreparation composed of two parts, or thereabouts, of crystalcopal-varnish, and one part, or thereabout, of a naphthaline or spiritVarnish, commercially known as copzalina. Vith this preparation I inkthe stone in the usual way. The impression taken upon said card beisgpurely superficial, by reason of the gum upon the card preventing theinking preparation from soaking thereinto, every dctail of theimprintisperfectly sharp and clear.

Said card is then placed upon the iron tablet with its unprinted sidenext the enamel and -both subjected to pressure, which imparts to theenamel upon the iron the subject exactly as it appears upon thestone,every line being perfectly clear and distinct. The tablet is thenlaid aside until the imprint thereon is partly set, or until it becomeswhat is technically known as tacky, and by reason of the high volatilityof the preparation used as ink a very few minutes will suffice for it toacquire this condition, and in the hands of askilled operrator this iseasily gaged.

Having previously decided upon the color or tint intended to be used, Iprocure this in very fine powder (which must in all cases be a mineralproduction) and dust this over the enameled imprinted tablet, or platepreviously described, the colored powder adhering only where saidimprint exists. The superfluous powder is then carefully dusted off,'

leaving the inked impression only perfectly covered with the color,every detail being still clearly preserved. The tablet or plate is thenor at any subsequent period, placed in a furnace and heated until thecolored imprint has become incorporated with the enamel, when it isremoved from the furnace and put aside to cool, and when cold presents aperfectly smooth and translucent surface, fully and clearly showingevery line and detail of the subject without causing the imprinted andcolored matter to become blurred or otherwise injured.

In order to facilitate the operation and economize time, I find inpractice that the best method of carrying out the operation is asfollows: Given that the desired subject is upon the stone and the twocards glazed, dried, and rolled and the number of iron plates or tabletsintended to be treated are enameled and ready for use, I take animpression from the inked stone upon one card and lay it aside. I thenreink the stone and place the second card thereon and take an impressionupon that in the following manner: Upon the back of the second card whenupon the stone I place the back of one of the iron tablets so that itsenameled face is uppermost, and upon this I place the first card withits imprinted side next the enameled face of the tablet; and tofacilitate the operation and prevent possible labor.

rupture of the enamel I place upon the top of the latter card athickfi'annel or felt, preferably of the same size as the card. Thewhole may then be subjected to pressure in the same manner andpreferably by the same means as lithographic printing generally. By thismeans the one pressure from the machine gives to the bottom card animprint of the matter upon the stone and the iron tablet an imprint ofthe matter upon the upper card. The upper card is then removedand thetablet taken away and dusted with color by a junior operative in themanner previously described. The bottom card may now be removed from thestone and laid aside in the same manner as the first. The stone may nowbe again reinked and the card that was first printed again placed uponthe stone in the same position as before, suitable register beingemployed for this purpose, as in lithographic printing generally. Aniron tablet is then placed upon this face upward and the remainingcardplaced thereon face downward, as before, and the operation repeateduntil the Whole of the tablets are printed and dusted with color. Bythis method I am enabled to perfect a saving in both time and It is notnecessary that the tablets should be put into the furnace immediatelyafter being dusted with the color in the manner described, but may be sotreated at any subsequent date, even to the extent of months, if needed,care of course being exercised that the matter thereon does not becomescratched or injured, so that a further saving of time is efiected byfurnacing a number of tablets together instead of one at a time.

Iron tablets treated as described are perfectly water-proof, and thedesigns imprinted thereon as durable and immovable as the designs orpatterns in ceramic and similar glazed or enameled earthenware, and anydesign or pattern may be so produced upon and within the enamel of theiron tablets in the manner described, and where necessary a picture ordesign with more than one color therein may be reproduced upon theenameled iron by repeating the described operation for each color, inthe same manner as lithographic printing upon paper.

Having now fully described my invention, what I claim, and desire tosecure by Letters Patent, is-

1. The herein-described method of ornamenting iron tablets, whichconsists in first drawing the desired design upon stone, then taking theiron tablet, which is suitably enam eled, and pressing upon the surfaceof the said enameled tablet a card-board sheet the surface of which isgummed and upon which is the design which has been transferred from thelithographic stone, then applying colored dust thereto, and subsequentlybaking the same, substantially as described.

2. The herein-described ink for the purpose specified, consisting of apreparation composed of crystal copal-varn'ish and copzalina, insubstantially the proportions specified.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

' JOSEPH (JAVALLI.

- Witnesses.

GEO. THos. HYDE, S. J. EARL.

